:root {
    /* Dark Mode (Default) - Earthy/Pastel Theme */
    --bg-color: #2b2b2b;       /* Soft Charcoal */
    --card-bg: #363636;        /* Lighter Charcoal */
    --text-main: #e3e3e3;      /* Bone White */
    --text-muted: #a8a8a8;     /* Soft Grey */
    --border-color: #4a4a4a;
    --input-bg: #404040;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.3);

    /* Sport Specific Colors (Pastel/Muted) */
    --color-swim: #89CFF0;     /* Pastel Baby Blue */
    --color-bike: #90EE90;     /* Pastel Light Green */
    --color-run: #FFB347;      /* Pastel Orange */
    --color-trans: #C0C0C0;    /* Silver/Grey */

    --accent-primary: #d6d6d6; /* Light Grey */

    --font-heading: 'Poppins', sans-serif;
    --font-body: 'Open Sans', sans-serif;
}

[data-theme="light"] {
    /* Light Mode - Earthy/Pastel Theme */
    --bg-color: #f7f5f0;       /* Cream/Paper */
    --card-bg: #ffffff;
    --text-main: #4a4a4a;      /* Dark Slate */
    --text-muted: #8c8c8c;
    --border-color: #e0e0e0;
    --input-bg: #fdfcf8;
    --shadow: 0 4px 15px rgba(0,0,0,0.05);

    /* Sport Colors (Slightly deeper for visibility on light) */
    --color-swim: #5D9CEC;     /* Soft Blue */
    --color-bike: #8CC152;     /* Grass Green */
    --color-run: #F6BB42;      /* Warm Yellow/Orange */
    --color-trans: #AAB2BD;    /* Blue Grey */

    --accent-primary: #757575; /* Medium Grey (for contrast on light bg) */
}

* { box-sizing: border-box; margin: 0; padding: 0; }

/* Theme transitions scoped to elements that actually change color/bg
   on theme switch, instead of every element. Avoids button-press flicker
   and the perf cost of a universal transition. */
body, header, .section-card, .preset-select, .input-wrapper input,
.time-input-container input, .total-section, .theme-btn, .slider,
.section-header, .total-display {
    transition: background-color 0.3s ease, color 0.3s ease,
                border-color 0.3s ease;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-color);
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    scroll-behavior: smooth;
}

/* --- Inline SVG icons --- */
.icon {
    width: 1em;
    height: 1em;
    fill: currentColor;
    flex-shrink: 0;
    display: inline-block;
    vertical-align: -0.125em;
}

/* The Font Awesome swimmer faces left; flip horizontally so it faces
   the same direction as the run icon. */
.swim-icon { transform: scaleX(-1); }

/* --- Header & Controls --- */
header {
    background-color: var(--card-bg);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

h1 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-primary);
    display: flex;
    align-items: center;
    gap: 10px;
}

.controls {
    display: flex;
    gap: 1rem;
    align-items: center;
}

/* Toggle Switch Styling */
.switch-container {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    font-weight: 600;
}

.toggle-switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 24px;
}

.toggle-switch input { opacity: 0; width: 0; height: 0; }

.slider {
    position: absolute;
    cursor: pointer;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    transition: .3s;
    border-radius: 24px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 16px;
    width: 16px;
    left: 3px;
    bottom: 3px;
    background-color: var(--text-muted);
    transition: .3s;
    border-radius: 50%;
}

input:checked + .slider { background-color: var(--accent-primary); border-color: var(--accent-primary); }
input:checked + .slider:before { transform: translateX(26px); background-color: #fff; }

.theme-btn {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-main);
    padding: 0;
    border-radius: 50%;
    cursor: pointer;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
}
.theme-btn:hover { color: var(--accent-primary); border-color: var(--accent-primary); }

/* --- Main Layout --- */
main {
    flex: 1;
    width: 100%;
    max-width: 900px;
    margin: 2rem auto;
    padding: 0 1rem;
}

/* --- Sections --- */
.section-card {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.section-header {
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-main);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

/* --- Distance Inputs --- */
.preset-select {
    width: 100%;
    padding: 0.8rem 2.5rem 0.8rem 0.8rem;
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    border-radius: 8px;
    font-family: var(--font-body);
    font-size: 1rem;
    margin-bottom: 1.5rem;
    outline: none;
    cursor: pointer;

    height: auto;
    min-height: 48px;
    line-height: 1.4;

    /* Custom Appearance to support wrapping */
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;

    /* Custom dropdown arrow */
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23a8a8a8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 1rem center;
    background-size: 1em;
}
.preset-select:focus { border-color: var(--accent-primary); }

.distance-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

.input-group label {
    display: block;
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 0.3rem;
}

.input-wrapper {
    position: relative;
}

.input-wrapper input {
    width: 100%;
    padding: 0.8rem 2rem 0.8rem 0.8rem;
    background-color: var(--input-bg);
    border: 1px solid transparent;
    border-bottom: 2px solid var(--border-color);
    color: var(--text-main);
    font-family: var(--font-body);
    font-size: 1rem;
    outline: none;
}

.input-wrapper input:focus {
    border-bottom-color: var(--accent-primary);
}

/* Remove default up/down arrows from number inputs */
input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

input[type=number] {
    -moz-appearance: textfield;
    appearance: textfield;
}

.unit-label {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 0.8rem;
    color: var(--text-muted);
    pointer-events: none;
}

/* --- Calculator Table --- */
.calc-row {
    display: grid;
    grid-template-columns: 1fr 1.5fr 1.5fr;
    gap: 1rem;
    align-items: center;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
}

.calc-row:last-child { border-bottom: none; }
.calc-row.header { font-family: var(--font-heading); font-weight: 600; color: var(--accent-primary); padding-bottom: 0.5rem; }

.sport-icon {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 600;
    font-size: 1.1rem;
}
.sport-icon .icon { width: 1.2em; height: 1.2em; }

/* Sport Specific Color Assignments */
.sport-icon.swim .icon { color: var(--color-swim); }
.sport-icon.bike .icon { color: var(--color-bike); }
.sport-icon.run  .icon { color: var(--color-run); }
.sport-icon.trans .icon { color: var(--color-trans); }

.time-input-container input {
    width: 100%;
    padding: 0.6rem;
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-main);
    text-align: center;
    font-family: var(--font-body);
    font-variant-numeric: tabular-nums;
    font-size: 1rem;
}
.time-input-container input:focus { border-color: var(--accent-primary); outline: none; }

.disabled-input { opacity: 0.3; pointer-events: none; border: none !important; background: transparent !important; }

/* --- Total Time --- */
.total-section {
    text-align: center;
    margin-top: 1rem;
    background: var(--input-bg);
    border: 1px solid var(--accent-primary);
}

.total-label {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}
.total-display {
    font-family: var(--font-heading);
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--text-main);
    font-variant-numeric: tabular-nums;
    line-height: 1.1;
}

/* --- Find Next Race section --- */
.race-links-section { text-align: center; }

.race-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    align-items: center;
}

.race-link {
    display: flex;
    align-items: center;
    height: 30px;
    transition: opacity 0.3s;
}
.race-link:hover { opacity: 0.75; }

.race-link img {
    height: 100%;
    width: auto;
    object-fit: contain;
    filter: brightness(0.9);
}

/* --- TriPlan section --- */
.triplan-section { text-align: center; padding: 1rem 1.5rem; }

.triplan-link {
    display: block;
    text-align: center;
    text-decoration: none;
    color: var(--text-main);
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 600;
}
.triplan-link:hover { color: var(--accent-primary); }

/* --- Focus visible (keyboard nav) --- */
:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
    border-radius: 4px;
}
/* Inputs already show their own focus border, so suppress the ring on them
   to avoid a doubled outline */
.input-wrapper input:focus-visible,
.time-input-container input:focus-visible,
.preset-select:focus-visible {
    outline: none;
}

/* --- Footer & Socials --- */
footer {
    text-align: center;
    padding: 3rem 1rem;
    background-color: var(--bg-color);
}

.footer-text {
    color: var(--text-muted);
    font-size: 0.8rem;
    margin-bottom: 1.5rem;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    align-items: center;
}

.social-links a {
    color: var(--text-muted);
    font-size: 1.8rem;
    transition: color 0.3s, transform 0.2s;
    text-decoration: none;
    line-height: 0;
}

.social-links a:hover {
    color: var(--accent-primary);
    transform: translateY(-3px);
}

/* --- Responsive --- */
@media (max-width: 768px) {
    header { padding: 0.8rem 1rem; }
    h1 { font-size: 1.3rem; }
    .controls { gap: 0.5rem; }
    .switch-container { font-size: 0.8rem; }

    /* Keep three-up distance grid on mobile but with tighter gap */
    .distance-grid { gap: 0.5rem; }
    .input-wrapper input {
        padding: 0.7rem 1.6rem 0.7rem 0.6rem;
    }
    .unit-label { right: 6px; }

    .calc-row.header { display: none; }

    .calc-row {
        grid-template-columns: 1fr;
        grid-template-areas: "sport" "pace" "time";
        background-color: var(--input-bg);
        border-radius: 8px;
        padding: 1rem;
        margin-bottom: 1rem;
        border: 1px solid var(--border-color);
    }

    .sport-icon { grid-area: sport; margin-bottom: 0.5rem; font-size: 1.1rem; }

    /* Add labels via pseudo-elements for mobile since header is hidden */
    .pace-wrapper::before { content: attr(data-label); display: block; font-size: 0.75rem; color: var(--text-muted); margin-bottom: 4px; }
    .time-wrapper::before { content: "Total Time"; display: block; font-size: 0.75rem; color: var(--text-muted); margin-bottom: 4px; }

    .total-display { font-size: 2.75rem; }
}